Solid tumors account for more than 90% of all human cancers. As the tumor grows, in order to sustain itself, it must develop its own blood supply. This blood supply, however, is much different from the blood supply to normal tissues. The blood vessels formed in tumors are typically highly irregular and tortuous. They may have arterio-venous shunts and blind ends, and lack smooth muscle or nerves and have incomplete endothelial linings and basement membranes. This leads to low overall levels of oxygen in most tumors. Many tumors have areas of extreme hypoxia. (Brown, J. M. “Exploiting the hypoxic cancer cell: mechanisms and therapeutic strategies.” Molecular Medicine Today Apr. 2000 (Vol. 6)).
Unfortunately, there is considerable evidence that hypoxic tumors are refractory towards many of the currently available treatments for solid tumor cancers, including radiation therapy and chemotherapy. Accordingly, there exists a need for a method of treating solid tumor cancers having hypoxic regions.
A second problem existing in medicine today is the need for reliable methods for eradication of pathogens in blood products. In the United States almost 4 million individuals are transfused every year with over 28 million blood components derived from nearly 13 million units of blood donated by apparently healthy volunteers. The blood components are extensively tested for the presence of pathogens prior to administration. Testing has reduced the risk of transmission of enveloped virus to a small but finite value in the developed world. The NIH has estimated the risk during transfusion of a unit of screened blood is 1/1,000,000 for hepatitis A virus (HAV), 1/30,000-1/50,000 for HBV, and 1/2,000,000 for human T-cell lymphotropic viruses (HTLV). The odds of transmission for parvovirus B19 is much larger 1/10,000. Parvovirus and HCV lack a lipid membrane envelope and have relatively poor odds of transmission, relative to other pathogens.
The solvent detergent (SD) method is used to eradicate enveloped virus and bacterial pathogens present in units of plasma protein. The lipid envelope of the pathogen is dissolved by the solvent detergent. The SD method cannot be used to eradicate pathogens present in platelet and red cell concentrates because the cells also contain lipid envelopes and will be lysed by the pathogen inactivation treatment. The SD method does not inactivate HCV and parvovirus in units of plasma protein because they do not contain a lipid envelope. Thus, there is an urgent need to develop technology that may eradicate non-enveloped pathogens in units of blood components.